Tyrannosaurus Rex, whose name means "tyrant lizard king", is classified as a bipedal carnivore (Therapoda) of the lizard-hipped dinosaur order (Saurischia).It had a large, sturdy head and long hind legs and a tail. In comparison, its arms were very short with two-fingered hands. What their actual purpose was is unclear. It is believed that T-Rex was able to balance skillfully and moved around on its two hind legs.